Just created an account here today after I completed the scenario as an ilevel 892 resto shaman. It's not impossible, and not all too difficult either after stage one imo. I even messed up a lot on the try I completed it. Didn't pay attention in stage one and ate an early Mana Sting that left me at about 30% mana for the rest of stage one, and also died an extremely stupid death in stage 2 - had ankh luckily though.

Will have the video uploaded eventually as well and I could edit it into this post if that's okay?

I just completed it on my Resto Shaman!!
Gear: itemLevel 901
Trinkets: Celestial Map 895+Darkmoon Deck: Promise (since cake does not work on the NPCs)
Legendaries: Played arount Elemental Rebalancers and Jonats, but I personally used Prydaz+Roots of Shaldrassil
Talents: Undulation(lvl15),Gust of Wind(lvl30),Lightning Surge Totem(lvl45), Crashing Waves(lvl60), Ancestral Vigor(lvl75),Echo of Elements(lvl90),Ascendence(lvl100
Stats: 28% Crit, 13%Haste, 103%Mastery
I used Prolonged Power on CD and ofc as PrePot.

As resto shaman i have two questions:
1) How can you make this huntress npc to move and stand in healing rain/spirit link?
2) Why 4th pack of mobs on 1st stage start alternating aoe and fixate after stun totem? That's no funny at all to run away from one of them while another casts his aoe spell.

Had many attempts in p1. It's very punishing for resto shamans because we don't have the best toolkit for breaking spells that can't be interrupted. When you've passed part 1 it should be smooth sailing from there.

P1 Talents:

1/2/1/1/3/3/1

You could probably run a High tides build but I'm a lot more comfortable with this build in dungeons. Graceful spirit helps with the kiting and you really need stun totem for the mages when they get a few stacks (You can also purge the stacks, but I didn't feel like wasting gcds on offensive dispels).

P1 Gear.

Sephuz - Great here, you can get it off each wave and with this build you can get off a lot of buffed Healing waves or healing surges.

Prydaz - Also great here, will shield you from the fixates and the occasional arcane blast.

Prydaz could be substituted with Roots or Velens, anything that is good in regular mythic+ is also good here.

4 set is crucial here, if you do not have 4 set I would try to run a high tides build instead.

P1 Approach

Save all stuns for mages, I usually interrupt a mage 2 times before stunning it. By then it will be on around 45% hp. Make sure you never get hit by the manadrain arrow, direct it to one of the melee npcs in your group.

When you stun the mages, make sure you hit the fixate npcs aswell, and when the stun is about to expire run away from them and put down a slow totem (if they have started to fixate you again)

I spread cds out to the 2 last waves, the last one is most dangerous so I tried to save HTT/SLT/Hero(Sense of urgency) to that wave, the second to last wave I used Ascendance.

After defeating the enemy force you will have room to change talents/gear and drink to your hearts content.

P2

Before the maze i changed to Prydaz/Kj trinket. The trinket probably shaves of a minute and it felt great to use here. You can also consider equipping another DPS trinket and a hidden satyr neck here, because the healing requirement is really low. I changed no talents.

When entering the round room that usually 2 lancers guard in m+ your shitty ragtag party (Seriously who thought it was a good idea to bring Granny along) will get captured by a Lich-like being wearing a pajamas. You have 5 minutes to go trough an easy enough maze and rescue them (By this point you’re probably not that fond of them but if you want shinies you need to save them).

Stagger your eye kills so you never risk dying, especially if you already died once(Reincarnation). You can purge the eye’s pulsing effect but we have ranged spells and need not worry.

When you’re done with the first set off eyes pop SWG and chain lightning the unstable orbs when entering the room. Kill off the bats quick with KJ trinket and chain lightning, if the bats don’t die quickly they will start to hurt. Just fisnish the dominator off with our mundane ST rotation.

Entering the next room, cleanse the Panicked soul. I’m note sure what the circle on that npc does, but I assume it fears you. After the dispel you heal up the Damaged souls, don’t do what I did and switch before one is topped off because they take damage until fully healed.

Engage the archer and hide behind the healed souls when she launches her mana drain arrow. This is a slight soft enrage, so as I mentioned before you might want to run a satyr neck and another dps trinket like Oakheart's Gnarled Root, you can also use stun totem on the first to save time..

Open the next gate and pop SWG and chain lightning your way up. Open the next gate and engage the Dread corruptor who captured your sucky 3man party. KJ trinket should be up here again, use it when entering so it does not splash on all the eyes.

Changed talents before P3 because I was not sure if vigor would buff the damaged npcs, I used the shield totem instead. I also changed to Belt+Velens, Velens help to heal your party while your managing the damaged npcs.

You need to heal 8 damaged npcs while healing your shitty party, the damaged npcs came in waves of 3. So use everything on the first 2 waves and try to get 2 fully healed on the 3rd wave.

Wave 1: Hero + Ascendance

Wave 2: Velens + HTT

Wave 3: Try to top off 2, but if you can’t make sure that atleast one gets fully healed (I was 100k health off on the npcs this wave, you can consider using only Hero on Wave 1 and save Ascendance to the 3rd wave).

If you get a 4th wave you should be atleast 7/8, Quickly heal one of the adds so you get 8/8 and the boss transitions. If more then 2 Gets turned you will have a tougher time before the final phase, which is fairly easy.

Did it on 4th attempt as restoration druid 904 yesterday. I recommend to take Tree of Life talent for the P3, because it's a lot easy to heal the souls with it.
Legos: chest and wrists; changed wrists to boots after saving guys. If I had prydaz, I would use it for sure instead of chest.

Some tips, that may be useful:

P1. For the waves with Mage and Soldier(s): use your typhoon to interrupt both Arcane Blitz and Knife Dance (when mage with 3 stacks starts casting, rogues start blade dancing as well).

P2. The eyes don't only explodes, but they also have small aoe aura, so don't stand near them. Use typhoon to knockback.

P3. For the 3 phase you will need all your abilities, so after saving your guys you can wait as long as you want before going further. I think it's the hardest part of challenge. I equipped legendary boots at that moment, so my tranquil easily topped the last wave of souls.
You may try to heal all 3 souls each time, but it's not necessary. The first wave I used Tree of Life form; the second - G'Hanir ability; the third without anything (I should probably buy drums of war and use here or on the 1st, but I was too lazy and did it without hero); the fourth wave I used tranquil. So I had 1 enemy mob after each wave except the 4th one. And it was really easy to beat these 3 mobs, just like phase 1.

P4. The last boss is easy. Always stand near the last fel pool. And make sure you always have 50%+ HP when he jumps on you. I tried to be always at this mark, so Ignite Soul can't kill my guys.

Did it yesterday on my rshammy after 4 tries 909 equip. Was fairly easy once u get the hang of it and was running with prydaz and jonats.

What screwed me in the first try was that when I reached ph3 I started attacking the mob before healing the damaged mobs to full to help me soak the mana sting so be careful to heal them up before you start attacking. Also in this phase dispel the guy running around in fear if you do not it will make the phase a lot harder.

Last tip I can give is to not be afraid to use all your cd's for the 5th phase. It is very important to prevent as many mobs as you can from reaching the boss, as if you pass this phase the last one is really easy (its pretty much Nightbane all over again). Use lust on that part for the first wave, take 2nd with HTT, and ascendance the 3rd (spam HS with stacks from tidal waves for the crit, but keep an eye on your party's health bar too as it is easy to forget about them). You can also precast GoTQ to heal your entire group going berserk on each other and possibly 1 or 2 incoming damaged mobs depending on the spawn. Also spirit link will work in that phase for your party even though they turn on one another.

Another thing that I discovered on my first try which screwed me over were my trinkets. I was running with Urn and Cake but the Cake apparently does not work on your party in the challenge, so I had to switch to a lower level trinket in the next try. Do not know if this is intended or not but I would like an official response from a CM.

I love that this entire healing challenge involves whole 1 dispell and optional purge if your class is capable of it...

I call this "run rhc group through end raid bosses" challenge.

Btw it seems that npcs gain hp and dps as you increase ilvl, at 890 pally they had 3.6mil hp and jarod did around 90k dps while at 900ilvl they have 4mil hp and jarod does around 160k dps.

I dont think npc dps is even an issue, as a paladin there are waves where i have to avoid dpsing because i dont want the next wave to come without my CC up. Phase 2 you wouldnt have npcs and it isnt really a dps check, and on the hardest phase which is 3rd, ur npcs will be whacking at each other and you really dont want them killing themselves with high dps. So yea low ilvl isnt really a big problem here.

After doing the Balance quest yesterday i tried this one this morning. Since Restro is my off specc i only wear 898 with Ring and Neck legos.

Did it on the 5th attempt and only p1 was hard for me. Wiped there 4 times but after the 5th add wave the rest was a joke, managed the rest in the first try.
My artifact lvl is 36 and i went the full run with this build: 3/2/3/3/3/3/3.

Part 1: -Try to stay next to the mages so u can interrupt both Arcane Blitz and Knife Dance at the same time.
-Dont forget to use War Stomp's AOE stun, if u choose the right RACE
-Always try to root the soldier, if he is focusing u just use DB or tank it in bear form.
-Use Drums and Int Potion for Wave 5, its the hardest wave.
-Try to force the Manastring on the warrior. The Roque dies very fast and this wiped me 2 times.

Part 3: I only managed to heal 2 every phase so i got 3 adds afterwards. Since i just random healed a the souls, i got 3 mages afterwards And this was very bad. U can imagine from Phase 1 how hard 3 mages hit with a lot of stacks. I used drums and managed to get to the last Phase

Part 4: Very easy, just try to stay at 50% hp when he jumps on u. than heal ur Party and wait for Ignite souls to fall of. Heal urself to above 50% and profit.

Compared to the Balance one this one was kinda easy, but still alot of fun.

Did it yesterday on my rshammy after 4 tries 909 equip. Was fairly easy once u get the hang of it and was running with prydaz and jonats.

What screwed me in the first try was that when I reached ph3 I started attacking the mob before healing the damaged mobs to full to help me soak the mana sting so be careful to heal them up before you start attacking. Also in this phase dispel the guy running around in fear if you do not it will make the phase a lot harder.

Last tip I can give is to not be afraid to use all your cd's for the 5th phase. It is very important to prevent as many mobs as you can from reaching the boss, as if you pass this phase the last one is really easy (its pretty much Nightbane all over again). Use lust on that part for the first wave, take 2nd with HTT, and ascendance the 3rd (spam HS with stacks from tidal waves for the crit, but keep an eye on your party's health bar too as it is easy to forget about them). You can also precast GoTQ to heal your entire group going berserk on each other and possibly 1 or 2 incoming damaged mobs depending on the spawn. Also spirit link will work in that phase for your party even though they turn on one another.

Another thing that I discovered on my first try which screwed me over were my trinkets. I was running with Urn and Cake but the Cake apparently does not work on your party in the challenge, so I had to switch to a lower level trinket in the next try. Do not know if this is intended or not but I would like an official response from a CM.

For the last stage with the ghosts, I would do a potion of prolonged power as soon as it says stage 4. This makes it so healing tide would heal all 3 ghosts to full, I'd use ascendance on the 2nd wave, and then just spirit link my crew for the 3rd as I healed the 2 ghosts up. Never had a leftover ghost doing it the 4 times I made it there.